The present invention relates to small arms ammunition and, more particularly, to a hollow-point projectile for an auto-loading pistol.
Recently, several law enforcement agencies, including the Law Enforcement Assistance Administration (L.E.A.A.) have developed criteria for the selection of handgun ammunition for use by law enforcement officers. In general, the criteria are: maximum muzzle energy, optimum penetration, minimum weight loss or fragmentation upon upset, and acceptable pressure loading, accuracy and reliability.
Optimum penetration is defined as six inches or less in tissue simulating gelatin. This limitation was adopted to protect bystanders who might otherwise be injured by a projectile passing through the intended target and further serves to insure that all the projectile energy is transferred to the target. High rates of energy transfer, coupled with a high muzzle energy, are desirable to instantaneously disable the target, thereby preventing return fire on the law officers and eliminating the need for further fire on the target.
High energy transfer, coupled with controlled or limited projectile penetration, is conventionally achieved by use of a "hollow point" configuration wherein a centrally disposed axially directed recess is provided in the projectile nose. Such a recess weakens the projectile nose such that, upon impact, the projectile "mushrooms", opening outwardly and backwardly, thereby presenting a greatly increased frontal area.
Reliability is measured in terms of functioning in an auto-loading pistol, a type of weapon being adopted by an increasing number of law enforcement agencies for increased fire power and ease of operation.
To insure proper feeding, and prevent "jamming", the projectiles, generally formed of lead or a soft lead alloy, must resist deformation, especially deformation of the projectile nose, prior to firing. Deformation resistance is presently achieved through the provision of a protective covering or jacket, generally of brass or, less frequently, steel.
Unfortunately, the jackets of presently available fully jacketed auto-loading ammunition, while preventing deformation prior to firing, also prevent the desired mushrooming upon impact. This may result in the projectile passing completely through the target without achieving the desired instantaneous disablement. A bystander may then be injured by the projectile, either by being in the path of the bullet as it exits the initial target, or by a ricochet off a hard object such as a building or automobile.
Attempts at promoting mushrooming of a jacketed, hollow point projectile have generally involved scoring, slitting or otherwise weakening the jacket in the area of the projectile nose. Projectiles of this type are not entirely satisfactory since the degree of expansion and depth of penetration area highly dependent on the projectile's velocity at the point of impact and with the uniformity among projectiles of the device used to weaken the jacket material. Therefore, under unfavorable conditions, the hollow point projectile may not expand, thereby allowing it to pass through the target or, in the other extreme, to fragment into several pieces causing massive and undue destruction of tissue. The gravity of the tissue destruction problem is increased by the fact that the jacket fragments, generally being brass, do not provide a clear X-ray image as does the lead portion of the projectile.